There are no applications for patent related hereto heretofore filed in this or any foreign country.
1. Field of Invention
This invention relates generally to power driven conveyors and more particularly to a board conveyor that receives an agglomeration of scrambled boards and unscrambles and aligns the boards perpendicularly to the conveyor course during conveyance.
2. Background and Description of Prior Art
Lumber manufacture in the modern time has become increasingly competitive to a point where its operations must be automated as much as possible for economic viability of the manufacturing process. In automating various lumber processing machinery it often is necessary to receive an agglomerated supply of scrambled boards, having longer dimensions extending somewhat in the same general direction, and turn the boards to a uniform parallel attitude while singulating them, individually or in small groups, in adjacency or at discrete intervals for delivery to other mechanisms for further processing. Machines accomplishing this function are commonly known in the lumber industry as xe2x80x9cunscramblersxe2x80x9d and the instant invention seeks to provide a new and improved form of such machine that resolves problems that have existed in previous unscrambling mechanisms.
Traditional lumber unscramblers, and those in common use in the present day, have provided an upwardly and forwardly extending conveyor generally having a linearly angulated course with sufficient slope that disorientated boards moving forwardly by reason of support on some type of cog or bar structure of the conveyor or on the conveyor support surface tumble rearwardly on the conveyor before the boards reach a forward position at the upper forward portion of the conveyor. Commonly, such linear unscramblers have had some type of a hopper, with or without a separate feeding mechanism, associated with their lower rearward course to receive a supply of scrambled boards, since no flat portion could be provided in the lower rearward course of such conveyors where boards could be dumped, accumulated or stored until they were moved, because of the lineal nature of the conveyor with a uniform slope throughout its course.
Unscrambling linear conveyors also have not been completely successful in unscrambling boards. They often allow one or more disoriented boards to be supported by the conveyor structure or other boards in a fashion to maintain their disorientated array, rather than being completely and directly supported on the conveyor or its support surface, without tumbling rearwardly for reorientation. This usually requires manual intervention of a workman to maintain proper functioning and tends to lessen efficiency and economic viability of the unscrambling process. Hopper structures have presented additional problems as generally scrambled boards must be reasonably well aligned, both lengthwise and in approximately parallel relationship, to be fed from a hopper orifice. When boards are not so aligned the feeding operation may and often does break boards as they leave the hopper and enter the conveyor through the hopper orifice or feeding mechanism between the hopper and conveyor to cause either the hopper orifice or feeding mechanism to become plugged and require manual intervention to maintain conveyor operation. Linear unscramblers, because of these problems and the essential nature of the conveyors, have relatively low production speed limitations and reliability.
The instant unscrambler seeks to eliminate or substantially lessen these problems by providing a conveyor having a vertically curvilinear course in the general configuration of an angulated upwardly and forwardly extending S-shaped curve. Such a curve allows definition of a relatively flat horizontal area in its lower rearward portion, where an agglomeration of scrambled boards may be dumped directly unto the conveyor without use of any type of intervening hopper structure, orifice or singulator to avoid the problems associated with these later structures. The curvilinear configuration of the conveyor also allows a more steeply rising medial portion that may approach a tangential angle of 75 degrees or more from the horizontal to make more certain the unscrambling of disorientated boards carried by a single cog or bar structure by uniformly causing excess boards to tumble rearwardly on the steeply curved portion of the conveyor. The S-type curvilinear configuration, however, still allows the unscrambled and aligned boards to be delivered at a spacedly forward, vertically distant point in aligned orientation for receipt by other processing equipment.
The use of such a curvilinear type conveyor course is allowed primarily by reason of the method of driving the link chain conveyor. Link chain conveyors with cogs, or more commonly with elongate bars carried between at least two laterally spaced chain courses, have heretofore been used in unscramblers having a linear course of travel, but such linear conveyors have been powered by driving mechanism in the forward or at least medial portion of the conveyor course that has provided only a pulling force on the link chains upwardly thereof to cause forward motion of the link chains with or without an underlying support.
Such linear link chain conveyors require relatively tightly supported chains to create a substantially linear chain course between the driving linkage and the rearwardly adjacent chain support structure because of the required tension in the chain to move boards at a practical speed for lumber processing. Because of the pulling action on the chain, if the chain were sufficiently slack to follow a curvilinear course it would not effectively or efficiently perform its conveying operation, if it would do so at all. The instant curvilinear conveyor in contradistinction drives the chains of the conveying flight of a conveyor at both the lower rearward end and the upper forward end. This method of powering the conveyor chains causes a pushing force on the rearward active portion of the chain and a pulling force on the forward active portion to allow the chains to be loosely maintained in open channels defined in the conveyor support surface between the spaced driving linkages. This maintains curvilinear configuration of the chains on the conveyor support surface channels to provide substantially more efficient unscrambling with greater speed than prior unscrambler chains and without mechanical structures limiting upward chain motion which may interfere with either board conveyage or unscrambling.
The use of conveying devices having a vertically curvilinear conveyor course to singulate and orientate various industrial and food products has heretofore become known in general, but it is not known that such conveyors have been used for elongate materials of substantial length such as lumber or have positionally maintained their chains in open guiding channels or without mechanical confinement or constraint of some chain portion. Such known curvilinear conveyors generally have had particular structures which would prevent or substantially limit their use with elongate boards. All such known conveyors have had upstanding sides at one or both lateral edges of the conveyor to define horizontally extending channels carrying an adjacent conveyor chain, or some support element associated with the conveyor or claim, to direct the curvilinear course of the chain. The instant unscrambling singulator has no such side structures either projecting above the curvilinear conveyor surface that supports and directs motion of the conveying chains or elsewhere. This construction allows scrambled boards to be placed on the instant conveyor without regard to the position of their ends in relation to the lateral edges to the conveyor and is allowed by reason of the particular drive mechanism for the conveying portions of the chains that pushes their lower rearward input ends and pulls their upper forward output ends.
If a board singulator and unscrambler has upstanding side edges, those edges may interfere with boards carried by the conveyor, especially in an area where delivered from a hopper, and such conveyors commonly require substantial human attention to properly position boards on the conveyor chains and assure proper board feed from a hopper or an associated feeding structure. Such unscramblers generally will not allow feeding by dumping an assemblage of scrambled boards on the chain to slow their speed of operation and have a higher probability of breaking boards or associated singulator or feeding mechanism by reason of disoriented boards, especially when used for boards of smaller cross sectional dimensions and irregular shape, such as stickerers reused to separate piled green lumber for kiln drying.
The instant unscrambler may be variously sized and configured for all of the types of boards dealt with in lumber processing, from short dimension blocks for finger gluing assemblage through slender stickerers of medial length to the longest and heaviest timbers having a length of twenty feet or more. The unscrambler also may be configured as a module for use in any lumber processing line with variable dimensioning of length, of height, of input and output zones and of width between the lateralmost conveyor chains.
Our invention resides not in any one of these features individually, but rather in the synergistic combination of all of the structures of our unscrambler that necessarily give rise to the functions flowing therefrom.
Our unscrambler generally provides a frame carrying drive mechanism and supporting conveying mechanism having an uppermost support surface carrying a link chain conveyor. The support surface comprises a horizontal ruled surface with an angulated S-shaped configuration in a vertical plane and defines at least two parallel upwardly opening spaced channels to carry conveyor chains on the support surface with bars extending over the support surface and between the chains to move boards on the conveyor. The vertically curvilinear shape of the support surface provides a substantially horizontal rearward portion to receive an assemblage of scrambled boards, a medial steeper portion where boards not properly unscrambled and arrayed on the conveyor automatically tumble rearwardly for further processing and a forward substantial horizontal portion to deliver unscrambled and aligned boards individually or in small groups for further processing. Drive mechanism carried by the frame provides an electric motor synchronously driving the conveyor chains both in their lower rearward and upper forward portions to push the rearward chain portions and pull the forward chain portion to move the chains while maintaining them in the channels to direct their course of motion.
In providing such a mechanism it is:
A principal object to provide an unscrambler that has a singulating and unscrambling conveyor for boards that is supported on a support surface configured as a horizontal ruled surface with an angulated S-shaped curvilinear configuration in a vertical plane.
A further object is to provide such an unscrambler support surface that has a lower rearward generally horizontal portion to receive an agglomeration of scrambled boards, a steeply angulated medial portion to cause improperly orientated boards to tumble rearwardly for further processing and an upper forward upper portion to deliver single or small groups of unscrambled and properly arrayed boards for further processing.
A still further object is to provide such an unscrambler that has an uppermost support surface defining at least two laterally spaced parallel open top channels to receive link chains of a conveyor and direct chain motion along the support surface to move boards thereover.
A still further object is to provide such a conveyor that has powered driving mechanism in the lower rearward portion of the active conveyor flight to push the lower portion of the conveyor chains forwardly and upwardly and in the upper forward portion of the conveyor flight to pull the forward portions of the conveyor chains forwardly to allow the chains to be movably carried between the driving mechanisms and yet maintain their course of travel in the open top channels defined in the support surface.
A still further object is to provide such an unscrambler that moves boards over the support surface so that the boards are supported by spaced bars extending between at least two spaced parallel conveyor chains.
A still further object to provide such mechanism that is of new and novel design, of rugged and durable nature, of simple and economic manufacture and one that is otherwise well suited to the uses and purposes for which it is intended.
Other and further objects of our invention will appear from the following specification and accompanying drawings which form a part hereof, but in carrying out the objects of our invention it is to be understood that its features are susceptible to change in design and structural arrangement with only a preferred and practical embodiment of the best known mode being specified and illustrated in the accompanying drawings as is required.